The embodiments herein relate to subterranean formation operations, and more particularly to methods for enhancing both suspension and transport of proppant particulates and subterranean formation fracture conductivity.
Hydrocarbon producing wells (e.g., oil producing wells, gas producing wells, and the like) are often stimulated by hydraulic fracturing treatments. In traditional hydraulic fracturing treatments, a treatment fluid, sometimes called a carrier fluid in cases where the treatment fluid carries particulates entrained therein, is pumped into a portion of a subterranean formation (which may also be referred to herein simply as a “formation”) above a fracture gradient sufficient to break down the formation and create one or more fractures therein. The general term “treatment fluid,” as used herein, refers generally to any fluid that may be used in a subterranean application in conjunction with a desired function and/or for a desired purpose. The term “treatment fluid” does not imply any particular action by the fluid or any component thereof. As used herein, the term “fracture gradient” refers to a pressure (e.g., flow rate) necessary to create or enhance at least one fracture in a subterranean formation.
Typically, particulate solids are suspended in a portion of one or more treatment fluids and then deposited into the fractures. The particulate solids, known as “proppant particulates” or simply “proppant” serve to prevent the fractures from fully closing once the hydraulic pressure is removed. By keeping the fractures from fully closing, the proppant particulates form a proppant pack having interstitial spaces that act as conductive paths through which fluids produced from the formation may flow. As used herein, the term “proppant pack” refers to a collection of proppant particulates in a fracture, thereby forming a “propped fracture.”
During hydraulic fracturing or other subterranean formation operations, particulates or particles other than proppant may be suspended within the treatment fluid (e.g., weighting agents, bridging materials, and the like). These particulates and/or particles are included in the treatment fluid to ensure that the treatment fluid is adequate to perform its given function and may vary depending on, for example, the conditions of the subterranean formation.
The specific gravity of particulates and/or particles used in a subterranean operation may be high in relation to the treatment fluids in which they are suspended for transport and/or deposit into a fracture. As such, the particulates and/or particles may settle out of the treatment fluids at any point during the operation. For example, the particulates and/or particles may settle to the bottom of a wellbore or may form a heterogeneous gradient throughout the treatment fluids. Additionally, the particulates and/or particles may settle out of the treatment fluid prior to reaching their intended target zone, thereby reducing their effectiveness in the target zone. For instance, proppant particulates may settle out of a treatment fluid toward the bottommost portion of the fracture, resulting in complete or partial occlusion of the portion of the fracture where no proppant particulates have collected when the hydraulic pressure is removed (e.g., at the top of the fracture or a bottom portion of the fracture above a bottommost portion). As such, the productivity of a subterranean formation may be impaired due to such settling.